Trying to dial in my QFT 750
The carb is at baseline, the only thing I changed was the IAB's 4 sizes larger to help with the carbon fouling of the plugs. I looked at the tslots yesterday before I took it for a drive and I squared them up. The one thing I did notice is 1 slot was longer than the other, so I kind of averaged it for the two. This carb came with the orange pump cam, not the blue. Timing is 18 initial and 35 total, I have not checked it with a vacuum gauge, but that is a simple check to do.
I maintain that fouling is generally more of a timing issue than carb related. 18 initial seems like a lot for that combo. My last combo was much gnarlier than yours is (idled at 1,100) and that's pretty much where my timing was set. Can I suggest backing it down a few degrees then re-set the idle to where you want it? See if that may give you an inch or two more vacuum. I have a hunch it might be easier to tune that way, you can always go back to where it was if it doesn't do anything. Are your ignition components in good shape? Maybe you need a one step hotter plug? Did you check the gaps, etc?
I also believe your part throttle issues are power valve related. That's where driving with the vacuum gauge comes in handy, you can see what vacuum you are cruising at and whether the power valve is dumping fuel unnecessarily.
Did you take the carb off to check the t-slots? They should be square under the throttle blades. .020" is the generally accepted measurement.
Do you have a fuel pressure gauge? If it's too high then you could be pushing fuel past the needle and seat but I doubt that here.
Where are your floats set? Does this carb have clear sight glasses? On a double pumper, Quick Fuel wants the floats set to be halfway up the glass, not just sloshing out the bottom when you shake the car like on an older Holley. Not sure what they would say about this carb though, maybe lower it a tad and see if it does anything.
And again, the blue pump cam and 33 nozzle seems like overkill. You didn't mention any bog off the line. I'd go back to the orange or maybe even a pink one if you have an assortment. The cams all deliver the same volume of fuel but over a different amount of time. Again, the blue is like quickly dumping the whole shot all at once while the other cams are more of a steady stream over the opening of the throttle.